Thailand is the second most popular destination country, and Bangkok is the most popular city for travellers who use the online travel platform Agoda.
The findings were based on data collected from January to May this year.
During the five-month period, Thailand ranked second to Japan.
Agoda also found that Thailand had the fourth highest number of domestic trips, following the United States, Japan and Malaysia.
Asia's travel booking platform Klook saw a 1,200% year-on-year increase in the number of foreign tourists reserving activities in Thailand through its site.
Tourists from Hong Kong made up the largest group of visitors who booked activities in Thailand, followed by those from Taiwan, Singapore, South Korea and Malaysia.
